Heat olive oil in a large skillet or cast iron skillet over medium-high heat.
Add chicken and season with salt and pepper. Cook for about 5 minutes, stirring occasionally.
Meanwhile, whisk all sauce ingredients together in a small bowl until combined
Once the chicken is browned, add broccoli, and stir to combine.
Continue cooking for an additional 3 minutes, until the broccoli is bright green.
Stir in the sauce, and cook until the sauce has thickened, about 2 minutes.
Remove from heat and stir in the sesame oil until combined.
Garnish with green onions and toasted sesame seeds, if desired.
Store leftovers in an air tight container and refrigerate for up to 5 days.
